Use of Plastic Correction Formula to Improve Accuracy of Welding Residual Stress Test with Blind-Hole Method

The blind-hole method is the most widely used approach to experimentally determine the distribution of residual stress. This paper aims to improve test accuracy of welding residual stress and conducts an experimental study on the strain release factors involved when using the blind-hole method for Q235 and Q345, two steels commonly used in building structures. The ranges of strain release factors A and B in the elastic stage, the effects of strain release factors on residual stress calculated values, and the plastic corrected strain release factors are analyzed considering of the effect of plastic deformation around the blind hole on measurement accuracy. Finally, a simplified calculation formula to determine strain release factors is proposed for use with the blind-hole method. Results show that in the elastic stage, strain release factor A for Q235 and Q345 ranges from-0.399 to-0.525 and strain release factor B from-0.791 to-0.960. Changing the strain release factors A and B shows that calculated residual tensile stress varies in relation to a decrease in both factor values. However, there is a increase in calculated residual compressive stress with a decrease in the strain release factor A value, but there is an decrease with a decrease in strain release factor B value. Calculated residual stress applied to elastic strain release factors is compared with that applied to amended plastic strain release factors for Q235 steel. The maximum deviation between calculated residual stress and test stress is reduced from 21.1 to 1.0%,and for Q345 steel from 26.5 to 1.2%. It is thus evident that the plastic correction formula proposed in this paper can be used in calculations when conducting a residual stress test.

Deep learning enhanced NIR-Ⅱ volumetric imaging of whole mice vasculature

Fluorescence imaging through the second near-infrared window(NIR-Ⅱ,1000–1700 nm) allows in-depth imaging.However, current imaging systems use wide-field illumination and can only provide low-contrast 2D information, without depth resolution. Here, we systematically apply a light-sheet illumination, a time-gated detection, and a deep-learning algorithm to yield high-contrast high-resolution volumetric images. To achieve a large Fo V(field of view) and minimize the scattering effect, we generate a light sheet as thin as 100.5 μm with a Rayleigh length of 8 mm to yield an axial resolution of 220 μm. To further suppress the background, we time-gate to only detect long lifetime luminescence achieving a high contrast of up to 0.45 Icontrast. To enhance the resolution, we develop an algorithm based on profile protrusions detection and a deep neural network and distinguish vasculature from a low-contrast area of 0.07 Icontrast to resolve the 100μm small vessels. The system can rapidly scan a volume of view of 75 × 55 × 20 mm3and collect 750 images within 6mins. By adding a scattering-based modality to acquire the 3D surface profile of the mice skin, we reveal the whole volumetric vasculature network with clear depth resolution within more than 1 mm from the skin. High-contrast large-scale 3D animal imaging helps us expand a new dimension in NIR-Ⅱ imaging.

In-situ study of the hydrogen peroxide photoproduction in seawater on carbon dot-based metal-free catalyst under operation condition

Hydrogen peroxide(H_(2)O_(2))photoproduction in seawater with metal-free photocatalysts derived from biomass materials is a green,sustainable,and ultra environmentally friendly way.However,most photocatalysts are always corroded or poisoned in seawater,resulting in a significantly reduced catalytic performance.Here,we report the metal-free photocatalysts(RUT-1 to RUT-5)with in-situ generated carbon dots(CDs)from biomass materials(Rutin)by a simple microwave-assisted pyrolysis method.Under visible light(λ≥420 nm,81.6 mW/cm^(2)),the optimized catalyst of RUT-4 is stable and can achieve a high H_(2)O_(2)yield of 330.36μmol/L in seawater,1.78 times higher than that in normal water.New transient potential scanning(TPS)tests are developed and operated to in-situ study the H_(2)O_(2)photoproduction of RUT-4 under operation condition.RUT-4 has strong oxygen(O_(2))absorption capacity,and the O_(2)reduction rate in seawater is higher than that in water.Metal cations in seawater further promote the photo-charge separation and facilitate the photo-reduction reaction.For RUT-4,the conduction band level under operating conditions only satisfies the requirement of O_(2)reduction but not for hydrogen(H2)evolution.This work provides new insights for the in-situ study of photocatalyst under operation condition,and gives a green and sustainable path for the H_(2)O_(2)photoproduction with metal-free catalysts in seawater.

Symmetric Variation of Monomers for Constructing 1D/2D Imine-Based Covalent Organic Frameworks

Synthetic control of topology connectivity is the crowning achievement for covalent organic framework(COF)fabrications.Although a large number of one-,two-,and three-dimensional(1D,2D,and 3D)COFs have been reported,their topology structure constructions are restricted to the use of symmetric monomers with the purpose of increasing the crystallinity and/or porosity.Herein,three imine-linked COFs with different topology nets(namely,sql-b and sql-c)were constructed by symmetric variation of monomers via the condensation of a tetra-amine monomer with a D2h-symmetry and lower C_(2v)-symmetric dialdehyde monomers,bearing a phenolic hydroxyl group at different positions.The results indicated that a reasonable introduction of the phenolic hydroxyl group could effectively tune the topological structure of COFs at the molecular level during the crystallization stage.Particularly,the remarkable difference in the dye uptake ability between these COF materials indicated that the fabricated specific pore geometries,as well as different steric hindrance and H-bonding interactions,played a pivotal role in accessing molecules in the solution.Therefore,this work might boost the explorations of COF materials with expected topologies and pore geometries from conventional monomers through bottom-up synthesis methodology by molecular designing and engineering.

L-GrAFT_(7) has High Accuracy in Predicting Early Allograft Failure after Liver Transplantation: A Multicenter Cohort Study in China

Background and Aims:Increasing utilization of extended criteria donor leads to an increasing rate of early allograft failure after liver transplantation.However,consensus of definition of early allograft failure is lacking.Methods:A retrospective,multicenter study was performed to validate the Liver Graft Assessment Following Transplantation(L-GrAFT)risk model in a Chinese cohort of 942 adult patients undergoing primary liver transplantation at three Chinese centers.L-GrAFT(L-GrAFT7 and L-GrAFT10)was compared with existing models:the Early Allograft Failure Simplified Estimation(EASE)score,the model of early allograft function(MEAF),and the Early Allograft Dysfunction(EAD)model.Univariate and multivariate logistic regression were used to find risk factors of L-GrAFT high-risk group.Results:L-GrAFT7 had an area under the curve of 0.85 in predicting 90-day graft survival,significantly superior to MEAF[area under the curve(AUC=0.78,p=0.044)]and EAD(AUC=0.78,p=0.006),while there was no statistical significance between the predicting abilities of L-GrAFT7 and EASE(AUC=0.84,p>0.05).Furthermore,L-GrAFT7 maintains good predicting ability in the subgroup of high-donor risk index(DRI)cases(AUC=0.83 vs.MEAF,p=0.007 vs.EAD,p=0.014)and recipients of donors after cardiac death(AUC=0.92 vs.EAD,p<0.001).Through multivariate analysis,pretransplant bilirubin level,units of packed red blood cells,and the DRI score were selected as independent risk factors of a L-GrAFT7 high-risk group.Conclusions:The accuracy of L-GrAFT7 in predicting early allograft failure was validated in a Chinese multicenter cohort,indicating that it has the potential to become an accurate endpoint of clinical practice and transitional study of machine perfusion.

Targeting modulation of intestinal flora through oral route by an antimicrobial nucleic acid-loaded exosome-like nanovesicles to improve Parkinson’s disease

Parkinson’s disease(PD)is one of the most prevalent neurodegenerative diseases.It is usually accompanied by motor and non-motor symptoms that seriously threaten the health and the quality of life.Novel medications are urgently needed because current pharmaceuticals can relieve symptoms but cannot stop disease progression.The microbiota-gut-brain axis(MGBA)is closely associated with the occurrence and development of PD and is an effective therapeutic target.Tetrahedral framework nucleic acids(tFNAs)can modulate the microbiome and immune regulation.However,such nucleic acid nanostructures are very sensitive to acids which hinder this promising approach.Therefore,we prepared exosome-like nanovesicles(Exo@tac)from ginger that are acid resistant and equipped with tFNAs modified by antimicrobial peptides(AMP).We verified that Exo@tac regulates intestinal bacteria associated with the microbial-gut-brain axis in vitro and significantly improves PD symptoms in vivo when administered orally.Microbiota profiling confirmed that Exo@tac normalizes the intestinal flora composition of mouse models of PD.Our findings present a novel strategy for the development of PD drugs and the innovative delivery of nucleic acid nanomedicines.

Evaluation of a newly developed oral and maxillofacial surgical robotic platform(KD-SR-01)in head and neck surgery:a preclinical trial in porcine models

Traditional open head and neck surgery often leaves permanent scars,significantly affecting appearance.The emergence of surgical robots has introduced a new era for minimally invasive surgery.However,the complex anatomy of the head and neck region,particularly the oral and maxillofacial areas,combined with the high costs associated with established systems such as the da Vinci,has limited the widespread adoption of surgical robots in this field.Recently,surgical robotic platform in China has developed rapidly,exemplified by the promise shown by the KangDuo Surgical Robot(KD-SR).Although the KD-SR has achieved some results comparable to the da Vinci surgical robot in urology and colorectal surgery,its performance in complex head and neck regions remains untested.This study evaluated the feasibility,effectiveness,and safety of the newly developed KD-SR-01,comparing it with standard endoscopic systems in head and neck procedures on porcine models.We performed parotidectomy,submandibular gland resection,and neck dissection,collected baseline characteristics,perioperative data,and specifically assessed cognitive workload using the NASA-TLX.None of the robotic procedures were converted to endoscopic or open surgery.The results showed no significant difference in operation time between the two groups(P=0.126),better intraoperative bleeding control(P=0.001),and a significant reduction in cognitive workload(P<0.001)in the robotic group.In conclusion,the KD-SR-01 is feasible,effective,and safe for head and neck surgery.Further investigation through well-designed clinical trials with long-term follow-up is necessary to establish the full potential of this emerging robotic platform.

USP19 suppresses inflammation and promotes M2-like macrophage polarization by manipulating NLRP3 function via autophagy

Macrophage polarization to proinflammatory M1-like or anti-inflammatory M2-like cells is critical to mount a host defense or repair tissue.The exact molecular mechanisms controlling this process are still elusive.Here,we report that ubiquitin-specific protease 19(USP19)acts as an anti-inflammatory switch that inhibits inflammatory responses and promotes M2-like macrophage polarization.USP19 inhibited NLRP3 inflammasome activation by increasing autophagy flux and decreasing the generation of mitochondrial reactive oxygen species.In addition,USP19 inhibited the proteasomal degradation of inflammasome-independent NLRP3 by cleaving its polyubiquitin chains.USP19-stabilized NLRP3 promoted M2-like macrophage polarization by direct association with interferon regulatory factor 4,thereby preventing its p62-mediated selective autophagic degradation.Consistent with these observations,compared to wild-type mice,Usp19−/−mice had decreased M2-like macrophage polarization and increased interleukin-1βsecretion,in response to alum and chitin injections.Thus,we have uncovered an unexpected mechanism by which USP19 switches the proinflammatory function of NLRP3 into an anti-inflammatory function,and suggest that USP19 is a potential therapeutic target for inflammatory interventions.

The development and function of follicular helper T cells in immune responses

Follicular helper T cells （Tfh） have been referred as a lineage that provides a help for B cells to proliferate and undergo antibody affinity maturation in the germinal center. Evidence has supported that Tfh subset development, like other lineages, is dependent on microenvironment where a particular transcriptional program is initiated. It has been shown that Bcl-6 and IL-21 act as master regulators for the development and function of Tfh cells. Tfh dysregulation is involved in the development of autoimmune pathologies, such as systemic lupus erythematosus, rheumatoid arthritis and other autoimmune diseases. The present review highlights the recent advances in the field of Tfh cells and focus on their development and function.

VEGF-B antibody and interleukin-22 fusion protein ameliorates diabetic nephropathy through inhibiting lipid accumulation and inflammatory responses

Diabetic nephropathy(DN)is considered the primary causes of end-stage renal disease(ESRD)and is related to abnormal glycolipid metabolism,hemodynamic abnormalities,oxidative stress and chronic inflammation.Antagonism of vascular endothelial growth factor B(VEGF-B)could effi-ciently ameliorate DN by reducing renal lipotoxicity.However,this pharmacological strategy is far from satisfactory,as it ignores numerous pathogenic factors,including anomalous reactive oxygen species(ROS)generation and inflammatory responses.We found that the upregulation of VEGF-B and downregulation of interleukin-22(IL-22)among DN patients were significantly associated with the progression of DN.Thus,we hypothesized that a combination of a VEGF-B antibody and IL-22 could protect against DN not only by regulating glycolipid metabolism but also by reducing the accumulation of inflammation and ROS.To meet these challenges,a novel anti-VEGFB/IL22 fusion protein was developed,and its therapeutic effects on DN were further studied.We found that the anti-VEGFB/IL22 fusion protein reduced renal lipid accumulation by inhibiting the expression of fatty acid transport proteins and ameliorated inflammatory responses via the inhibition of renal oxidative stress and mitochondrial dysfunction.Moreover,the fusion protein could also improve diabetic kidney disease by increasing insulin sensitivity.Collectively,our findings indicate that the bifunctional VEGF-B antibody and IL-22 fusion protein could improve the progression of DN,which highlighted a novel therapeutic approach to DN.

Geometric modeling of underground ferromagnetic pipelines for magnetic dipole reconstruction-based magnetic anomaly detection

To aid the magnetic anomaly detection(MAD)of underground ferromagnetic pipelines,this paper proposes a geometric modeling method based on the magnetic dipole reconstruction method(MDRM).First,the numerical modeling of basic pipe components such as straight sections,bends and elbows,and tee joints are discussed and the relevant mathematical formulations for these components are derived.Next,after analyzing the function of MDRM and various element division strategies,the sectional division and blocked division methods are introduced and applied to the appropriate pipeline components to determine the volume and center coordinates of each element,establishing the general models for the three typical pipeline components considered.The resulting volume and center coordinates of each component are the fundamental parameters for determining the MAD forwarding of underground ferromagnetic pipelines using the MDRM.Finally,based on the combination and transformation of the basic pipeline components considered,the visualized geometric models of typical pipeline layouts including parallel pipelines,pipelines with elbows,and a pipeline with a tee joint are constructed.The results demonstrate the feasibility of the proposed method of geometric modeling for the MDRM,which can be further applied to the finite element modeling of these and other components when analyzing MAD data.Furthermore,the models with output parameters proposed in this paper establish a foundation for the inversion of MAD.

Efficient photothermal CO_(2) methanation over Ni Fe alloy nanoparticles with enhanced localized surface plasmon resonance effect

The methanation of CO_(2) using green hydrogen not only consumes CO_(2) as a carbon resource but also stores H_(2) with high density.However,the activation of CO_(2) molecules under mild conditions is challenging due to their inert nature.Herein,we report an efficient photothermal catalytic system using light irradiation which realizes the complete conversion of CO_(2) to methane without external heating.Over optimum bimetallic Ni Fe nanoparticles(NPs)with a Ni/Fe atomic ratio of 7,the CO_(2) conversion can reach up to 98%with a CH_(4) selectivity of 99%,and no catalyst deactivation was observed for more than 100 h,outperforming the reported catalysts.The catalytic performance is strongly dependent on the structure promoters,light absorption efficiency,Ni Fe particle sizes,and Ni/Fe ratio.The Ni Fe alloy NPs with an average size of~21 nm dispersed on alumina nanosheets are evidenced to enhance the localized surface plasmon resonance(LSPR)effect,thus efficiently triggering the CO_(2) methanation.This work emphasizes and clarifies the important role of LSPR in CO_(2) hydrogenation,which may benefit the rational utilization of CO_(2) using solar power.

Study of the effect of chemical composition on the surface wettability of three-dimensional graphene foams

The chemical composition obviously affects the surface wettability of a three-dimensional(3D)graphene material apart from its surface energy and microstructure.In the hydrothermal preparation,the heteroatom doping changes the chemical composition and wettability of the 3D graphene material.To realize the controllable surface wettability of graphene materials,aminobenzene sulfonic acid(ABSA)was selected as a typical doping agent for the preparation of nitrogen and sulfur co-doped 3D graphene foam(SNGF)using a hydrothermal method.Different from using o-ABSA or p-ABSA as the dopant,SNGF with tunable surface wettability is obtained only when m-ABSA is used.This result indicates that the substituent position of-SO3H group in the benzene ring of ABSA is rather important for the tunable wettability.This work provides some theo retical foundations for dopant selection and some new insights in manipulating the properties of 3D graphene foams by adjusting the configuration of dopants.

The future of organ-oriented research and treatment

Organ-oriented research platform is based on machineperfusion(MP)technology providing continuous oxygenand nutrient supply for harvested organs.It permitsin vivo and in vitro investigation and represents one of thelatest innovations in the quest for a model to explore eitherphysiological or pathological processes of the whole organ.Recently,the ex vivo animal perfusion model has provento be an effective and reproducible translational researchplatform(1).

Contrast-enhanced fluorescence microscope by LED integrated excitation cubes

Fluorescence microscopy is a powerful tool for scientists to observe the microscopic world,and the fluorescence excitation light source is one of the most critical components.To compensate for the short operation lifetime,integrated light sources,and low excitation efficiency of conventional light sources such as mercury,halogen,and xenon lamps,we designed an LED-integrated excitation cube(LEC)with a decentralized structure and high optical power density.Using a Fresnel lens,the light from the light-emitting diode(LED)was effectively focused within a 15 mm mounting distance to achieve high-efficiency illumination.LEC can be easily designed in the shape of fluorescence filter cubes for installation in commercial fluorescence microscopes.LECs’optical efficiency is 1–2 orders of magnitude higher than that of mercury lamps;therefore,high-quality fluorescence imaging with spectral coverage from UV to red can be achieved.By replacing conventional fluorescence filter cubes,LEC can be easily installed on any commercial fluorescence microscope.A built-in LEC driver can identify the types of LEDs in different spectral bands to adopt the optimal operating current and frequency of pulses.Moreover,high-contrast images can be achieved in pulse mode by time-gated imaging of long-lifetime luminescence.

Optimization of magnetic anomaly detection with single-axis sensor for pig locating in low latitude areas

When a pig mounted with permanent magnets gets stuck in the pipeline,it can be located by detecting the magnetic anomalies on the ground using a single-axis magnetic sensor.In order to collect the magnetic anomaly efficiently through single-axis magnetic sensor,a geometric detection model and calculation method for singleaxis magnetic anomaly detection is established in this paper.The distribution of magnetic inclination and declination of the measuring points is obtained.The results indicate that the magnetic inclination of all measuring points vary within a small range of 2°,and this value is highly dependent on the magnetic sensor which is configured aboveground around the geomagnetic inclination.However,the magnetic declination at different points of detection surface is subject to the geomagnetic components and the Y-axis component of the magnetic field of magnets.The magnetic declinations distribute irregularly and vary in a wide range.Therefore,to achieve a high-efficiency detection with the single-axis sensor,the sensor shall be placed in such a manner that the magnetic inclination thereof coincides with the geomagnetic inclination.The magnetic declination of the sensor can be calculated using s,the superposed Y-axis component induced by the permanent magnets,and the corresponding formula given in this paper.The article demonstrates the feasibility of locating a blocked pig in the pipeline based on the single-axis magnetic anomaly detection.It will have a practical significance in guiding the engineering detection.

Design and Testing of a Novel Piezoelectric-Driven Microvibration Hammerhead

A novel microvibration hammerhead consists of a piezoelectric actuator and a double cross-shape compliant mechanism(DCCM)is presented in this paper.The output force of the piezoelectric actuator can be detected in real time by an insideinstalled pressure sensor.A theoretical model including the stiffness,first natural frequency,and stress of the DCCM and the displacement output of the piezoelectric actuator are established,and then they are further analyzed using the finite element analysis method.The effects of the beam thickness on the static and dynamic properties are deeply analyzed and compared.A prototype micro hammering system is constructed by integrating the microvibration hammerhead assembly and controlling system.Various experiments are also carried out to verify the basic performance of the micro hammering system.

Special Topic: Novel Sensing Materials and Their Applications in Analytical Chemistry

Over the past years,the development and analytical applications of sensors and sensing materials which are pursued with great interest by many researchers have shown a tremendous potential growth.These studies and applications require interdisciplinary synergism in material,electrochemical and measurement methodological fronts.